When professionals such as landscapers; golf course maintenance crews; lawn maintenance and property managers, as well as individual homeowners attempt to cut the grass and maintain their lawns; they often encounter tree roots and even cypress knees that protrude above of soil level. If a homeowner or professional attempts to use lawn mowing equipment over the exposed root, the chances are great that the spinning blade of the equipment will end up striking the protruding root and sustain substantial damage to one or more of the mower blade, spindle shaft, deck housing or even the motor. Tree root strike damage could render the equipment totally inoperable. The cost of repairs and or replacement could be substantial.
Managers of golf course greens, public parks and recreational areas are able to resurface exposed tree roots that have become tripping hazards to prevent or avoid possible lawsuits from injured parties. However, most homeowners and small commercial landscapers lack an appropriate tool for conveniently resurfacing a root. Many who encounter roots are tempted to inappropriately use the tip of a chain saw for resurfacing. However, this is highly inappropriate chain saw use and risks kickback damage to the saw and injury to the user.
Several types of gas powered edging devices are currently available for residential and profession use. Unfortunately, these devices are not well suited for grinding down (i.e., resurfacing) protruding tree roots. When such devices are used to resurface a root, surrounding soil severely dulls and eventually destroys the cutting edges of the blade.
U.S. Pat. No. 4,924,571 to Albertson describes a cutting tool suitable for girdling a tree and cutting through tree branches and small tree trunks. The cutting tool is frustoconical in shape and has a single length of chainsaw chain wrapped in a spiral groove around the outside face of frustoconical body. A steel pin secures the one end of the chain to the body. The opposite end is maintained using an adjustment screw and an adjustment cylinder. The frustoconical shape results in different cutting speeds at different axial locations.
Additionally, to achieve cutting throughout the axial length, the Albertson device must be tilted. However, because of the different speeds, such a device has a strong tendency to travel in a circular path, making stabilization extremely difficult. Another problem is inevitable loosening of the chain. The pin and screw in Albertson are prone to failure, as they are subjected to considerable impacts and stresses during operation. If either end becomes free, the device is extremely dangerous and self-destructive. If both ends become free, the chain becomes a dangerous projectile.
Another problem is that the Albertson device does not allow adjacent rows of saw teeth to be positioned in a preferred arrangement. The chain configuration and geometry of the frustoconical body determine the arrangement of adjacent rows of saw teeth. Thus two right angled teeth may be adjacent to one another resulting in an uneven cutting path. Moreover, the saw teeth are traveling at a less than optimal angled path, rather than a straight path. Chain saw blades are designed to cut when moving in a straight path. The angled path exaggerates or diminishes cutting angles of the toothed blades relative the cutting surface. The angled arrangement also tends to urge the chain laterally off the sprocket.
Yet another problem with the Albertson device is that one damaged tooth may require replacement of the entire length of chain. Frequently one tooth is damaged upon encountering a small stone.
The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above.